The impact of agricultural insurance on farmers’ income: Guangdong Province (China) as an example

This paper aims to test whether agricultural insurance significantly impacts farmers’ income increase or not. We have used the ordinary least squares method (OLS), panel fixed effects, and system generalized moment estimation (GMM) for the test. The results show that the increase in agricultural insurance density and the increase in agricultural insurance per capita compensation positively impact farmers’ income growth significantly. Agricultural insurance density and per capita compensation are the indicators used in this article to measure agricultural insurance development. Therefore, it can be considered that the development of agricultural insurance in Guangdong Province (China) can effectively increase the income level of farmers. Based on the results of theoretical and empirical analysis, combined with the current situation of agricultural insurance development in Guangdong Province, this paper finally puts forward relevant countermeasures and suggestions. It provides some ideas for giving full play to the role of agricultural insurance in promoting farmers’ income from the perspectives of pertinent system design, subsidy methods, insurance innovation, service level, and publicity.


Introduction
Agriculture is the basic industry of China's national economy, and it plays an irreplaceable strategic role in the process of China's take-off from a small agricultural country to economic power. Guangdong Province is at the forefront of reform and opening up in the country. The province's economic development is among the best in the country, with developed industries and high levels of urbanization, but there is also the problem of uneven development within the region. As far as the province is concerned, the three agricultural issues have not been fully resolved. As agriculture plays a fundamental role in developing secondary and tertiary industries in the fast-growing Guangdong Province, the issue of agricultural development cannot be ignored.
Guangdong Province is located in the southeast coastal area. Bai [1] pointed out that Guangdong is a typical "climate fragile area" with solid convective weather such as typhoons and heavy rains in summer, freezing disasters and droughts in winter mountains, and the frequency of natural disasters. And the intensity is at the forefront of the country, causing a severe impact on agricultural production. Agricultural insurance is an effective risk transfer tool, which is significant for improving the resilience of the farming output, reducing the losses caused by natural disasters to agrarian production, and protecting farmers' overall income. It is also significant in transferring agricultural risks, economic compensation, and financing. Several impacts have been taken into measure, the most critical of which is reducing farmers' income volatility. Although agricultural insurance plays a certain role in promoting agricultural development and stabilizing farmers' income, what impact will it have on farmers' income growth? What is the mechanism and extent of the impact? How the government and insurance companies should play the role of agricultural insurance is still unclear. More scholars are paying attention to the research on economic development in Guangdong Province. Research on the relationship between farmers' income is even rarer. This article considers the contemporary theme of agricultural development and the importance of agricultural insurance in solving the three rural issues, combined with the current academic research results and gaps, and determines the research theme.
Agricultural insurance in Guangdong Province has been trial-run since 1985 and has undergone a very long development process. From 1985 to 1989, Guangdong Province began to explore the development of agricultural insurance, which was initially held in the form of Chinese private insurance companies. The average annual premium of agricultural insurance in Guangdong Province during the five-year period was about 4.2 million yuan, and the comprehensive loss rate reached 95%, which was challenging to operate. As of 2019, Guangdong Agricultural Insurance has provided 78.2 billion yuan of risk protection for agricultural production, and the number of provincial-level insured varieties has reached 23. with the scale of agricultural insurance premiums reaching 6.222 billion yuan, the depth of agricultural insurance reaching more than 1.2%, and the density of agricultural insurance reaching 500 yuan per person. The income of agricultural insurance premiums has increased exponentially, from 53 million in 2007 to 1.882 billion yuan in 2019, indicating that the development of agricultural insurance under financial subsidies has achieved excellent results. It can be found that agricultural insurance premium income varies greatly from municipality to municipality.
In the Pearl River Delta region, except For Guangzhou, agricultural insurance premium income is low. In Shaoguan, Meizhou, Qingyuan, Zhanjiang, Maoming, and other cities, agricultural insurance premium income is higher, reaching 100 million to 300 million yuan. These five cities are rich in agricultural resources, creating space for the development of agricultural insurance. The agricultural insurance premium income of Jiangmen, Yangjiang, Zhaoqing, Heyuan, and Yunfu is in the second echelon, and the premium scale is about 60 million to 8000 yuan. In addition, the development of agricultural insurance in the remaining Foshan, Zhongshan, Dongguan, Chaozhou, Jieyang, and other areas is relatively backward.
At present, many scholars have paid attention to the problems of agricultural insurance and agricultural production and have obtained specific research results, which provide some ideas and enlightenment for the research of this article. At the same time, the research of this article also has specific innovations. From the perspective of research methods, most of the research results of predecessors used time-series data for research and mainly used static panel model analysis due to the lack of consideration of autocorrelation issues. This paper selects the panel data of 20 cities in Guangdong Province from 2010 to 2019, constructs a panel model of fixed effects and system generalized moments, and corrects the estimation bias caused by the endogenous information problem of the lag term of the explained variable. In this paper, the threshold effect model used by Shi [2] is adjusted in combination with Zhou's [3] method, which enriches the threshold to a certain extent. The research idea of the effect also supplements the research on agricultural insurance at the provincial level in Guangdong Province. From the perspective of research, most of the previous studies are based on the national or regional level, but few studies consider this issue from the standpoint of Guangdong Province. The research in this article has achieved high quality for Guangdong agricultural insurance to a certain extent.
This article provides a theoretical basis for effectively playing the role of agricultural insurance. Many scholars in China and abroad have paid attention to agricultural insurance issues, mainly focusing on the nature of agrarian insurance, influencing demand factors, impact on farm output and income of farmers, etc. But, research on the impact of Guangdong agricultural insurance on farmers' income is temporarily limited. Based on previous studies, this paper uses the agricultural insurance data of 20 cities in Guangdong Province in the past ten years as the research basis and uses empirical research methods to test the impact of agricultural insurance on farmers' income. It enriches the research ideas of agricultural insurance issues at the provincial level to a certain extent.
This paper is constructed as follows: the first section is the introduction, which includes the research gap, research significance, and key research questions. The next part is a literature review where we have added related previous studies from Chinese and international scholars. Chapter three discusses the research methodology. Chapter four presents the empirical analysis, and the next chapter explains the results of the investigation. In the last chapter in the conclusion, we have added the study's summary, limitations, and future scope.

Research on the influencing factors of agricultural insurance demand
Scholars have researched the influencing factors of farmers' demand for agricultural insurance. They mainly believe that the demand for agricultural insurance is not only affected by farmers' income. Abraham et al. [4] used a three-stage sampling procedure to select 120 rural households in their research. A questionnaire survey concluded that age, education level, and agricultural income could influence farmers' willingness to participate in agricultural insurance. Moschini and Hennessy [5] believe that farmers' risk preferences will affect whether they participate in agricultural insurance, and farmers with high-risk tolerance tend to bear themselves, but risk-averse people may not use agricultural insurance to transfer risks. King & Singh [6] found that insurance demand is replaced by access to private transfers. However, participation in a farmer's union contributes to understanding why farmers value index insurance. Coble et al. [7] proposed that it is usually a single economic factor that affects farmers' participation in agricultural insurance and includes farmers' risk awareness and crop risk status. The study by Sujarwo et al. [8] proposed that the scale of agriculture, the experience of purchasing agricultural insurance, and even the willingness of farmers' group meetings will impact farmers' willingness to accept agrarian insurance. In addition, Age, female gender, and prior insurance experiences all appear to favor participation in the insurance policy [9].

Research on the impact of agricultural insurance on farmers' income
Scholars' views are divided into two major sides in studying the impact of agricultural insurance on farmers' income. Some believe that agricultural insurance positively affects agricultural output and farmers' income, and others hold the opposite view. As early as the 1980s, Yamauchi [10] used farmers who purchased rice insurance in Aomori Prefecture, Japan, as the research object. He found that compulsory agricultural insurance helped stabilize farmers' income, especially in severe disasters. Xavier et al. [11] studied farmers who purchased storm insurance in southern India and found that agricultural insurance effectively increased the income of the local farmers. Hosseini & Gholizadeh [12] and Enjolras [13] found that agrarian insurance can positively reduce farmers' income volatility and increase farmers' income. Scholars such as Leatham [14] conducted field investigations on the development of agricultural insurance in North Dakota, the United States, and concluded that for every dollar of agrarian insurance compensation farmers receive, their final income would increase by $1.03. Barry [15] concluded through statistics that farmers' income in the years exposed to agricultural risks exceeds more than half of the normal production years, which illustrates the positive impact of agricultural insurance on farmers' income. Babcock and Hart [16], Glauber et al. [17], in their research results, all believe that although agricultural insurance increases agricultural output, it will shift the supply curve to the right, and thus the price of agricultural products will fall, but it will not necessarily increase farmers' income in the end. Through statistical data testing, Robert et al. [18] found that the impact of agricultural insurance on farmers' income is not necessarily significant, and even in some years, the two have a reverse relationship.

Research on the nature of agricultural insurance
For the research on the nature of agricultural insurance, many scholars believe that agricultural insurance has the attribute of public goods. For example, in Tuo and Wang's [19] study, agricultural insurance has both the attributes of private goods and public products, a quasi-public product. Feng & Su [20] also believe that agricultural insurance is not a personal good; it has apparent externalities. Zhang [21] proposed that the failure of the agricultural insurance market is precisely due to its positive externalities. Zhang and Chen [22] proposed that agricultural insurance should be carried out as a government's beneficial agricultural project rather than a purely commercial operation. Zhang [23] further proposed that the government should adopt diversified subsidy methods to support the healthy development of agricultural insurance. Liu and Sun [24] also believe that implementing premium subsidies can further promote farmers' willingness to participate in agricultural insurance.

Research on the impact of agricultural insurance on agricultural output
Many scholars have researched agricultural insurance and agricultural output. Most scholars believe there is a significant positive correlation between agricultural insurance and agricultural output. Akinrinola & Okunola [25] evaluated the success of the Nigerian Agricultural Insurance Scheme's goals in Ondo State. The study demonstrates that the farmers' participation in the insurance program was solely motivated by their ability to get financing. On the other hand, the farmers claimed that more investments had led to higher gains in output. Scholars such as Feng [26] and Fei [27] believe that agricultural insurance can promote agrarian output to a certain extent. Zhou & Zhao [28] and Wang [29] used a dynamic panel model to conduct empirical analysis and concluded that agricultural insurance has largely promoted agricultural production. Scholars such as Huang & Pu [30], Cheng et al. [31], and Jiang & Zhang [32] also believe that agricultural insurance can increase agricultural output.
In contrast, some scholars do not believe there is a strong relationship between these two. For example, Zhang et al. [33] assume that under the condition that the level and proportion of agricultural insurance subsidies are low, the total production of agricultural products will not significantly change. Hu [34] analyzed the impact of agricultural insurance on agricultural production capacity by hypothesis testing, and the results showed that the impact is almost non-existent, and there is no significant correlation between agricultural insurance and food production.

Research on the direction and path of agricultural insurance's impact on farmers' income
Some scholars have researched the issue of agricultural insurance on farmers' income. Jiang [35] believes that agricultural insurance under financial subsidies significantly affects farmers' income. Yuan et al. [36], Sun & Chen [37] analyzed based on the data of Jilin Province and found that agricultural insurance also promoted the income growth of local farmers to a certain extent. Zhang & Sun [38] used panel data from 31 provinces across the country to perform a cluster analysis and found that agricultural insurance played a certain role in promoting the growth of farmers' income from a national perspective. However, other scholars believe that the impact of agricultural insurance on farmers' income is not necessarily noticeable. For example, through cluster analysis, Yang and Shi [39] found that china's agricultural insurance did not significantly increase farmers' income. Hou et al. [40] also pointed out that agricultural insurance plays a small role in promoting farmers' income growth. Zhu & Tao [41] tested the impact of agricultural insurance on farmers' income through panel data and found that agricultural insurance not only does not Promote the increase of farmers' income but also has a significant negative effect.
Scholars have different opinions regarding agricultural insurance's impact on farmers' income. Zhou et al. [42] believe that agricultural insurance can protect farmers' income, but this protective effect only appears in post-disaster compensation. Zhang & Sun [38] used cluster analysis to divide 31 provinces into six regions and used the Hausman test method and generalized least squares (GLS) estimation method to conduct empirical research and found that agricultural insurance can significantly increase farmers' operating income. According to them, the effect of agricultural insurance on financial subsidies is more prominent. Fei et al. [43] believe that agricultural insurance reduces the fluctuation of farmers' income through the payment of indemnities and the promotion of agricultural technology by insurance companies. Lu et al. [44] stated that agricultural insurance is carried out through financial subsidies in the form of transfer payments to increase farmers' income, and there are obvious differences in the internal mechanisms of farmers' income increase in eastern and western China.

Research methodology
This article analyzes many Chinese and foreign agricultural insurance documents on agricultural production and farmers' income and documents on the development of agricultural insurance in Guangdong Province. It sorts out the mechanism and path of agricultural insurance's impact on farmers' income and further analyzes the impact of agricultural insurance on farmers' income. At the same time, it also analyzes other related factors affecting farmers' income, which provides a certain basis for the selection of control variables in the empirical analysis of this article. In addition, we have considered related theories, such as expected utility theory, welfare economics affect approach, and non-Walrasian equilibrium theory, to explore their application in agricultural insurance and provide a foundation for a thorough understanding of the nature of agricultural insurance. That helped us for improving the theoretical level of this article.
Considering the availability and completeness of the data, the per capita disposable income of farmers reflecting the income level of farmers is selected as the explanatory variable. The relevant indicators of the development level of agricultural insurance are used as the explanatory variables. The urbanization rate, mechanization level, industrial structure, and agricultural investment level are added as control variables. The data studied in this paper are all from the China Insurance Yearbook from 2011 to 2020, the Guangdong Statistical Yearbook from 2009 to 2020, the Guangdong Rural Statistics Yearbook, the China Rural Research Database, and the Chinese Rural Research Database.
The empirical analysis is an important research method for this article. After referring to the practice of Zhou (2018) and other scholars, this article uses ordinary least squares, fixed effects, and system generalized moment estimation methods to analyze whether agricultural insurance impacts farmers' income. On this basis, referring to Shi [2] and Li [45], a panel threshold model was established to test the characteristics of the impact of agricultural insurance on farmers' income. First, by collecting and sorting out the relevant data of 20 cities in Guangdong Province (except Shenzhen) from 2009 to 2019, establish a static panel model, use Stata 15 software to operate, and compare the results obtained with the estimated results of the dynamic panel model. Next stage, we analyzed the test results of the system GMM that considers the endogenous problem. Subsequently, a panel threshold model was established to test whether there is a threshold value for agricultural insurance density and per capita compensation. Finally, an objective, standardized, and rigorous empirical analysis conclusion can be drawn to test whether the hypothesis in this article is correct, and this article is summarized research conclusions accordingly.
A statistical income probability distribution method is adopted to explore further the role of agricultural policy insurance in guaranteeing farmers' income. After analyzing, we have made the following four hypotheses: (1) The risk hazards faced in the agricultural production process are lucid; the hazards either occur or do not occur. The probability of occurrence is set to P, and the likelihood of non-occurrence is 1-P. And 0<P�1.
(2) The income of farmers in production and operation obeys the binomial distribution: either no loss occurs, and the income is Y at this time, or there is a loss, and the loss causes the current production and operation income to be 0.
(3) Assuming that farmers' proficiency in production technology, crop quality, and other factors are consistent, there are two ways for farmers to avoid production risks: participating in agricultural insurance (M) and not participating in agricultural insurance (N).
(4) assuming that the premium of agricultural insurance is B. The government subsidy ratio for agricultural insurance is L. When the loss does not occur, the farmer's income is Y. Otherwise, it is 0, but at this time, the actual income obtained by the farmer who purchases agricultural insurance is A, 0<A�Y.
Therefore, the income probability distributions of farmers who purchase policy-based agricultural insurance and those who do not purchase policy-based agricultural insurance are obtained when risks occur and when risks do not occur, as follows (Table 1): From Table 1, it can be concluded that the expected benefits of farmers who purchase agricultural insurance and those who do not purchase agricultural insurance are:

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Let ϕ = PA−B, where PA is the insurance compensation farmers who purchase agricultural insurance expect to receive. If the amount is equal to the premium B paid when buying agricultural insurance, the farmers believe that there is no need to participate in the insurance, so the enthusiasm for buying agricultural insurance is not high. However, since most of the existing agricultural insurance in Guangdong Province is policy-based, the government subsidizes farmers' premiums relatively. Therefore, the premiums paid by farmers themselves must be lower than the expected indemnity PA, ϕ = PA− The existence of B = PA−(1−L)B>0 means that farmers' participation in agricultural insurance can increase their expected income. Therefore, theoretically, agricultural insurance can increase farmers' expected income.
To study the impact of agricultural insurance on farmers' income, we must first sort out the mechanism of agricultural insurance's effect on farmers' income. The impact of agricultural insurance on farmers' income is complex to a certain extent. After sorting out and thinking about the previous research results, this paper believes that the effect of agricultural insurance on farmers' income is mainly transmitted through direct and indirect paths. For reference, Zhou [46], Wang [47], and Li [48] put forward the idea which summarizes the impact of agricultural insurance on farmers' income into direct and indirect mechanisms, as shown in Fig 1. This paper studies the impact of agricultural insurance in Guangdong Province on farmers' income. Considering the availability and completeness of the data, the per capita disposable income of farmers, which reflects the income level of farmers, is selected as the explanatory variable, and indicators related to the level of agricultural insurance development are used as the explanatory variable. Then add urbanization rate, mechanization level, industrial structure, agricultural investment level, etc., as control variables. The data studied in this article are from the "China Insurance Yearbook" from 2011 to 2020, the "Guangdong Statistical Yearbook" and "Guangdong Rural Statistical Yearbook" from 2009 to 2020, the China Rural Research Database and AREMOS China Agricultural Statistics Database collects and sorts out the required data indicators.

An empirical analysis of the effect of Guangdong agricultural insurance on farmers' income increase
This article uses agricultural insurance density (ind), Per capita income of farmers (y), and per capita compensation expenditure (ex) to express the development level of agricultural insurance, which are measured by agricultural insurance premium income/rural population and agricultural insurance indemnity expenditure/rural population, respectively. Agricultural insurance density refers to farmers' expenditure in a certain area to transfer risks during the production process, that is, the average insurance premium paid by farmers, which can reflect the level of agricultural insurance development in a region. The greater the agricultural insurance density, the greater the level of agricultural insurance development in the region. The higher the value, the more obvious the role of agricultural insurance in protecting farmers' income. Per capita indemnity expenditure refers to the insurance indemnity compensation received by farmers due to disasters-the post-disaster effect of agricultural insurance to help farmers resume reproduction and stabilize farmers' income. Generally speaking, the larger the value, the higher the development of agricultural insurance. However, when the insurance compensation expenditure is large, it also means that there are many risk accidents and the farmers suffer a lot. Therefore, from the perspective of theoretical analysis, the direction of this indicator's impact on farmers' income levels cannot be determined.
To study the impact of agricultural insurance on farmers' income and consider the core variables, to be rigorous in the empirical analysis, it is also necessary to consider other factors affecting farmers' income. Based on the existing research results of the predecessors and considering the actual situation that affects farmers' income, this paper selects the other five control variables, which are as follows: (1) The level of urbanization (urb). Based on the particularity of China's urban-rural dual structure, although Guangdong Province has a highly developed economy, there is still a gap between urban and rural areas. Urbanization is an inevitable process of local social development. Wang [49] found that the level of urbanization is related to farmers' income. Wang's [50] research directly proposed that the urbanization rate can effectively increase farmers' income. (2) The level of agricultural mechanization (mec). The level of agricultural mechanization refers to the proportion of machinery and equipment used in agricultural production in the total workload. Traditional production methods require substantial labor costs, while advanced production technology can save agricultural production costs, improve agricultural production efficiency, and increase farmers' income to a certain extent. (3) Industrial structure (ins). In economic accounting, the gross product value of a country or a region is mainly composed of the output value of the primary, secondary, and tertiary industries, and the industrial structure refers to the proportion of each industry's three major industries. (4) Agricultural investment level (inv). The level of agricultural investment

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represents the degree of importance the government and social capital attach to agricultural production. The more significant the value, the more fixed assets are used in agricultural production, including modern machinery and equipment, high-quality seeds, fertilizers, etc., which can positively promote agricultural output. (5) The per capita planting area of crops (area). Taking this indicator as one of the control variables, it is mainly considered that the planting area of crops is one of the important factors affecting agricultural output. Zhou [46] believes that under certain production technologies, the larger the per capita planting area of crops, the greater the value of agricultural output.

Model construction
The time selected for the empirical analysis data in this paper is the relevant data of each city (except Shenzhen) in Guangdong Province from 2010 to 2019. The specific representation methods and data characteristics are shown in Table 2, and descriptive statistics for each variable are in Table 3.
This paper refers to the modified C-D production function of Zhou et al. [42] and Clarke et al. [51]. The following static panel measurement model is established, initially using ordinary least square & Two methods of multiplication and panel fixed effects are used for Yi Among them, C is a constant term, and the value of i is 1-20, which means that in the 20 prefectures and cities in Guangdong Province except for Shenzhen, the value of t is 1-10, which means 2010-2019. indit ; exit ; insit ; areai t ; mecit ; urbit ; invi t respectively refer to the agricultural insurance density, agricultural insurance per capita planting area of agricultural insurance, percentage of mechanized agricultural investment per capita, percentage of agricultural investment in the first industry, the proportion of agricultural investment per capita, and the proportion of agricultural investment per capita. Data in year t in the i-th city. Considering that the static panel model ignores the endogenous problem of the lag term of the explained variable, the estimation result may be biased.
Therefore, the dynamic panel model is further established, and the specific expression form is as follows: Among them, L.Y refers to the per capita income of farmers in the ith city in year t-1, that is, the per capita income of farmers in year t The above model tests the linear relationship between agricultural insurance and farmers' income, but it fails to consider the non-linear relationship. To further explore the impact of agricultural insurance on farmers' income, this article adds a threshold effect model to examine whether the impact of agricultural insurance's pre-disaster and post-disaster effects on farmers' income has a threshold effect and refers to the practice of Lin [52]. Set as a single threshold effect, as follows: Yi α1 and α2 are coefficients, and γ1 is the threshold value. The above two models respectively study whether the impact of agricultural insurance density and agricultural insurance per capita compensation on the per capita income of rural residents shows significant differences within different threshold intervals to study further the characteristics of agricultural insurance's impact on farmers' income.

Panel data unit root test
Before processing panel data containing time series, to avoid using non-stationary series data for regression, the phenomenon of "pseudo-regression" usually appears the stationarity of the data must be tested first. This article's type of panel data is similar to that of Zhou et al. [42]. Therefore, this article refers to the practice of previous scholars and uses the LLC unit root test method to verify whether the panel data is stable. The null hypothesis of the LLC test is that there is a common unit root. The test results are shown in Table 4. The P-value of each variable test is less than 0.01. The null hypothesis is rejected at the 1% significance level, indicating that all variables do not contain unit roots. Therefore, the next step of regression analysis can be performed on this variable data set, and no "pseudo-regression" problem indicates that the null hypothesis is rejected at the 1% significance level.

Direct mechanism
(1) and (2) in Table 5 are the estimation results using the ordinary least squares method and panel fixed effect. The former ignores the individual differences among the 20 cities in Guangdong Province, while the panel fixed effect improves this problem. The result is better than the former. However, neither of the above two static panel models can account for the lagging items of farmers' income, which will cause a large gap between the regression results and reality. Therefore, this paper also uses the System GMM (System GMM) method to estimate. This method considers the individual differences between each city's samples and avoids the endogenous problem caused by the autocorrelation of the farmers' income lag. From the P value of AR(2) and the P value of Sargan's test, we can see that the system GMM model does not have second-order autocorrelation, nor does it have the problem of over-recognition and the estimated result is relatively reliable.
Judging from the test results of the three models, the agricultural insurance density is positively correlated with farmers' income to different significant degrees. According to the above analysis, the system generalized moment estimation results are considered to be better than the other two methods. Therefore, the following analysis will be based on the test results of this method. From the results in Table 5, it can be seen that the lag term (LY) of farmers' income is significantly positively correlated with farmers' per capita income (Y) at the level of 1%, indicating that the previous period's per capita income of farmers will positively affect the current period's income. Per capita income of farmers. At the same time, the current agricultural insurance density also has a significant positive impact on farmers' income. The estimated coefficient is 0.017, which means that when the agricultural insurance density increases by 1 unit, farmers' income can increase by 0.017 units.
Although farmers may experience a decrease in income in the short term after paying premiums, in the long run, this conclusion is consistent with the operating conditions of agricultural insurance. The density of agricultural insurance represents agricultural insurance

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coverage in a certain area, and an increase in the density of agricultural insurance represents more farmers in the area. Under normal circumstances, insurance companies will provide professional disaster prevention and loss prevention services for participating farmers, including training, donations of materials, etc., to improve farmers' ability to prevent risks, thereby reducing the probability of risks caused by human factors. When risks occur, the degree of loss of farmers' income can also be reduced through mitigation work, and this positive effect will be reflected as the insurance company's underwriting experience and service level improve. Therefore, the increase in agricultural insurance density will positively impact farmers' income in the long run. Secondly, after participating in agricultural insurance, farmers can be more daring to try new technologies in the production process, thereby increasing the efficiency of agricultural output and helping farmers increase their income. Schultz [53] proposed that the popularization of agricultural insurance can change the risk appetite of farmers to a certain extent, is conducive to the promotion of advanced agricultural technology, and helps to promote farmers' income. Furthermore, using agricultural insurance can encourage farmers to expand their production scale. Cai et al. [54] took a live pig and reproductive sow insurance as examples. Both found that farmers who purchased live pigs and reproductive sow insurance will further expand the production scale, thereby significantly increasing the value of output and boosting income. Finally, most of the agricultural insurance currently on the market enjoys financial

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The impact of agricultural insurance on farmers' income subsidies from the central or local governments. After the effect of financial support for agriculture and farmers is reflected through the role of agricultural insurance, it can promote the development of rural finance and economy in the region, and increasing Farmers' income also has a beneficial effect. Therefore, it is reasonable to believe that increasing agricultural insurance density can significantly increase farmers' income, and the previous hypothesis is valid.

Indirect mechanism
To test the impact of the indirect mechanism of agricultural insurance on farmers' income, we continue to use farmers' income (Y) as the explained variable and agricultural per capita compensation as the core explanatory variable. Other control variables remain unchanged. The test results are listed in Table 6. The test result also considers the impact of the farmers' income lag. At the same time, the P values of AR(2) and Sargan tests are greater than 0.05, indicating that there are no second-order series correlation and over-identification problems.
The results show that agricultural insurance's per capita compensation expenditure (ex) positively correlates with farmers' income at a significant level of 1%. The estimated coefficient is 0.035, which means that when the per capita compensation for agricultural insurance increases by one unit, the per capita income of farmers can increase by 0.035 units. First, when a disaster occurs in agricultural production and operation and causes losses, insurance companies can reduce the loss of farmers by paying insurance indemnities and allowing farmers to have the funds to continue production and quickly resume reproduction. Secondly, due to the different subsidy ratios and protection levels of different agricultural insurance types, farmers may adjust the agricultural production structure based on the previous agricultural losses and

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are more inclined to choose crops with high-risk protection and large subsidy ratios to optimize production structure, helping stabilize income. Furthermore, for areas where risks frequently occur, on the one hand, insurance companies will adjust premiums and underwriting conditions accordingly to improve risk management; on the other hand, farmers will not only increase risk prevention awareness after receiving compensation from risks, Can also further realize the vital role of agricultural insurance, thereby increasing the insurance rate to ensure the stability of agricultural production and operation. Finally, because of the economic compensation function of agricultural insurance, it can guarantee crops and provide a suitable environment for promoting the development of rural finance. At present, emerging financial business models such as policy credit enhancement and policy mortgage loans are being promoted, which supports the economic development of rural areas and thereby encourages the increase of farmers' income.
In addition, the test results found that the industrial structure (ins), urbanization rate (urb), and per capita planting area of crops significantly impact farmers' income. The proportion of the agricultural industry structure is positively correlated with farmers' income. Even though the proportion of the primary industry in the three industries in Guangdong Province is gradually decreasing, and farmers' income is gradually increasing, the proportion of the industrial structure will change in the long run, Which represents the continuous adjustment and optimization of the industrial structure, and the continuous improvement of social resource utilization efficiency. From the perspective of economics, improving resource utilization efficiency promotes the overall economic level of society, thereby increasing farmers' income. With the acceleration of urbanization, more laborers will be transferred to cities and towns, and the number of farmers engaged in agricultural production will decrease. Those who stay in the countryside will have the opportunity to obtain more means of production and land for operation, which will help increase farmers' income.

Threshold effect on farmers' income
To further study whether there are threshold characteristics for the impact of agricultural insurance on farmers' income, this paper continues to use the threshold effect model to conduct empirical testing and put the agricultural insurance density and compensation into the inspection model.
The threshold effect test is first performed on the model to determine the number of thresholds. The test results are shown in Tables 7 and 8. At a significance level of 1%, for formula  under the null hypothesis with 1 threshold effect, the statistic of F is 20.15, and the P-value is 0.0933. The test result shows that it cannot be rejected. The original hypothesis indicates that agricultural insurance density's impact on farmers' income has a single threshold effect, and the threshold value is 28.861. The test results of (formula 8) have the same characteristics, the P-value is 0.07, and the threshold value is 14.892. In the double-threshold test, both p-values

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are greater than 0.1, accepting the null hypothesis that "there is no double-threshold," indicating no threshold effects of 2 or more. Table 9 shows the estimation results of the model parameters of agricultural insurance density and farmers' income sheet threshold. The threshold estimation results show that the threshold value of agricultural insurance density is ind = 28.681. Regardless of whether the threshold is crossed or not, agricultural insurance density positively correlates with farmers' income at a significant level of 1%. At the same time, when agricultural insurance density ind <28.681, the positive correlation coefficient of agricultural insurance density on farmers' income is greater. This shows that compared with areas with higher agricultural insurance density, each increase in insurance density has a greater impact on farmers' income in areas with lower agricultural insurance density. Table 10 shows the estimation results of the model parameters of agricultural insurance per capita compensation and farmer's income statement threshold. The threshold estimation results show that the threshold value of agricultural insurance per capita compensation is ex = 14.892. Similar to the agricultural insurance density threshold estimation result, whether above or below the threshold, the per capita compensation of agricultural insurance can always positively affect farmers' income at a significant level of 10%. At the same time, when the per capita compensation ex of agricultural insurance is less than 14.892, the positive correlation coefficient of the per capita compensation of agricultural insurance to farmers' income is greater. Increasing a unit's insurance compensation has a greater impact on farmers' income.
Generally speaking, agricultural insurance has less impact on farmers' income in areas with higher agricultural insurance density and higher per-capita insurance indemnities. In areas with lower agricultural insurance density and lower per capita insurance indemnities, agricultural insurance significantly impacts farmers' income bigger. This phenomenon shows that although agricultural insurance has a significant positive impact on farmers' income, the effect of agricultural insurance on the increase of farmers' income is not infinite. As a risk

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management tool, agricultural insurance can increase farmers' income to a certain extent from the perspective of transferring risks and guaranteeing production, but it cannot be used as the fundamental driving force to increase farmers' income. In addition, participating in agricultural insurance requires a certain cost, and holding agricultural insurance activities requires realistic risk requirements. Otherwise, it will increase the burden of farmers' insurance premiums; farmers may be interested in agriculture in areas with high agricultural insurance density.
Higher insurance dependence slack in daily operation and management is more likely to occur moral hazard, which is detrimental to farmers' income growth. In areas with low agricultural insurance density, farmers pay more attention to production management and take more proactive measures to prevent them. Risk, at this time, every increase in the density of agricultural insurance by one unit will bring more obvious effects on farmers' income. The high per capita compensation for agricultural insurance does not necessarily mean that agricultural insurance development is higher. It may be due to improper operation and management of agricultural insurance and immature mechanisms that have led to increased compensation due to the serious damage to local agriculture. Insurance companies have increased compensation expenditures. However, even with insurance protection, it may not cover farmers' income fully. It is not surprising that all losses have a small impact on farmers' income when per capita compensation is large. In addition, from an economic point of view, when farmers receive less indemnity, each additional unit of indemnity can bring A greater marginal effect; at this time, agricultural insurance significantly impacts farmers' income.

Conclusion
This paper uses static and dynamic panel models to test whether agricultural insurance significantly impacts farmers' income increases. This study uses the ordinary least squares method, panel fixed effects, and system generalized moment estimation test. This article analyzes the system's generalized moment estimation results considering the endogenous problem by selecting test results. The test results show that the increase in agricultural insurance density and the increase in agricultural insurance per capita compensation positively impact farmers' income growth significantly. Agricultural insurance density and agricultural insurance per capita compensation are the indicators used in this article to measure the level of agricultural insurance development. Therefore, it can be considered that the development of agricultural insurance in Guangdong Province can effectively increase the income level of farmers.
The threshold model test found that in different insurance density ranges and insurance compensation areas, the effect of agricultural insurance on farmers' income is significantly different. In areas with low agricultural insurance density, the impact of agricultural insurance on farmers' income is more significant than in High-density areas. We believe farmers will pay more attention to daily production and operation management in areas with low agricultural insurance density and low per capita compensation to prevent future risk losses. The participation of agricultural insurance will not make them slack in management; on the contrary, It will increase their confidence in the current output and psychological expectations and make them more actively carry out production activities to increase their income levels. In areas where agricultural insurance density is high and per capita compensation is high, farmers may become dependent on insurance to a certain extent, and even moral hazards may occur, and management slack may occur. Although the economic compensation function of agricultural insurance can stabilize their income, it is not the Source of motivation for increasing farmers' income. It should also be based on the scale of production and the level of agricultural modernization to improve farmers' income. From the above conclusion, we would like to suggest improving system design and vigorously promoting the development of agricultural insurance in Guangdong Province. Insurance subsidies must be carefully planned to be "smart," in the sense that they are efficient in accomplishing their fundamental goals, reduce difficulties with disincentives, and do not add to the government's mounting financial burden. Governments should also ensure that the fundamental public goods required to establish an environment conducive to insurance are in place before subsidizing insurance since, without them, neither insurance markets nor subsidies can be expected to function as intended [55]. Although policy-oriented agricultural insurance boosts farmers' incomes overall, it has a considerable variability on farmers in various income brackets, and this effect is stronger as farmers' incomes rise [56]. In the future, China should place a high priority on the design of a differentiated subsidy system and adhere to the principle of demand orientation to prevent agricultural insurance from becoming the catalyst for a widening income gap in rural areas as a result of its aggressive development of policy-based agricultural insurance over time.
Thus, related government departments and insurance companies must do their respective jobs efficiently. New policies should strengthen disaster prevention and loss prevention and improve post-disaster compensation levels. It is also suggested to divide risk areas and scientifically determine insurance rates. Furthermore, the government should Increase publicity in relatively backward areas and increase farmers' willingness to apply for insurance. This paper mainly studies the impact of agricultural insurance in Guangdong Province on farmers' income. The research method specifically compares the empirical results of the static panel model and the dynamic panel model and uses the threshold effect model to explore the characteristics of the impact of agricultural insurance on farmers' income. Although there are certain innovations in research perspectives and ideas, this article has some shortcomings due to limited research capabilities. On the one hand, due to the difficulty of data collection, this article uses annual panel data from 20 cities in Guangdong Province. The results of the empirical regression may deviate slightly from reality. In the selection of control variables, we mainly refer to previous studies. The selection of indicators may not be typical factors affecting farmers' income in Guangdong Province. We have not screened and analyzed the indicators that may affect the explained variables one by one. In addition, this article's research angle and thinking direction may have certain limitations, and it is impossible to consider all the influence mechanisms, which may also impact the research conclusions.